A 27-year-old African-American man with known sickle cell trait presents with recurrent painless gross hematuria. CT urography is unremarkable for stones or mass. Urine culture is sterile. The most likely underlying lesion explaining his bleeding is:

• A IgA nephropathy
• B Papillary necrosis of the renal medulla ✓
• C Renal vein thrombosis
• D Transitional cell carcinoma of the bladder

Explanation

Even heterozygotes (sickle cell trait) can sickle in the hypertonic, acidic, hypoxic renal medullary vasa recta, because these conditions favor HbS polymerization regardless of overall genotype. Repeated medullary sickling causes papillary necrosis and impaired urinary concentrating ability, making painless hematuria the classic renal manifestation of sickle cell trait. IgA nephropathy typically follows synpharyngitic hematuria, renal vein thrombosis presents with flank pain and proteinuria, and malignancy is excluded here by negative imaging.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.